FreeNAS scrubs during Time Machine x2, Life Preserver + more

[root@freenas] ~# zpool scrub strawberry
[root@freenas] ~# zpool scrub tallhalf
[root@freenas] ~# zpool status
  pool: strawberry
 state: ONLINE
status: The pool is formatted using a legacy on-disk format.  The pool can
	still be used, but some features are unavailable.
action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
	pool will no longer be accessible on software that does not support feature
	flags.
  scan: scrub in progress since Sun Jan 31 06:33:56 2016
        90.7M scanned out of 495G at 1.59M/s, 88h32m to go
        0 repaired, 0.02% done
config:

	NAME                                          STATE     READ WRITE CKSUM
	strawberry                                    ONLINE       0     0     0
	  ada1                                        ONLINE       0     0     0
	  gptid/bcc4af50-c5ff-11e5-b19e-001cc0bf031a  ONLINE       0     0     0

errors: No known data errors

  pool: tallhalf
 state: ONLINE
  scan: scrub in progress since Sun Jan 31 06:34:04 2016
        157M scanned out of 213G at 3.20M/s, 18h55m to go
        0 repaired, 0.07% done
config:

	NAME                                          STATE     READ WRITE CKSUM
	tallhalf                                      ONLINE       0     0     0
	  gptid/867f6402-c5ef-11e5-81b7-001cc0bf031a  ONLINE       0     0     0

errors: No known data errors
[root@freenas] ~#